Daytime Running lights

[CareyO]

Daytime Running lights.  2000 Silverado 2500.  Scan tool found trouble code "B2647.  Followed diagnostics in manual.  I Have 5 volt reference to sensor.  No short to ground and no short to power on signal wire.  Replaced Ambient light sensor and still have code B2647.  When I use 3 amp fused jumper i get scan code "B2648 - Ambient light sensor circuit high".  I put a 150 Ohm resister in place of the light sensor and I have DRL working.  Just have to use headlight switch to turn headlights on manually.  I bought a second Ambient light sensor and have the same problem.  Did I get two bad sensors or is there a parameter that need to be changed in the BCM?  The sensor shows resistance change on a Volt ohm meter when I move the sensor from dark to light.  I bought AC-Delco part # 15-72446,  GM#15740822, Made in Mexico.

[Jsdirt]

If it worked with a resistor, the sensor is the problem. You might have the wrong part number. GM is famous for mid year changes. Could be a different p/n for early vs. late '00.

[hexumaz]

I have an 01 1500hd and had the same problem, turned out it was the wrong part number. The one you bought is for auto climate control I believe. I bought ACDelco 12450120 and now the auto headlights and DRLs function properly.


Sent from my iPhone using Tapatalk

[CareyO]

Thank you for the info.  I bought from Amazon and it said compatible with my 2000.  I will search this part number 12450120

[Doug_Scott]

Well, it had to happen eventually.  This is the first time I have seen a post from someone actually trying to fix the DRLs since the internet opened up for widespread public access. 

[Jsdirt]

The very first thing I did to my Silverado, the minute I got home from the dealership in '07, was yank 2 fuses related to the DRLs. They haven't been in there since. 

[CareyO]

I like things working right, besides I can turn them off at any time just push the button.

[CareyO]

update:  The part number you gave me "12450120" fixed my issue. Thank you for the help.

[Jsdirt]

Thanks for the follow up!